complete dropdown
make sure to throw RecordNotFound (aka 404) for invalid levels

Also combine 2 show methods
merge
Merge pull request #104 from code-dot-org/trophydropdown

complete dropdown
Update user menu. Fix "are you a teacher?" link.
Fix anon user bug
[Finishes 59297334, 58860712]: new links in header
merge
Provide a git-revision-based cache_bust parameter to blockly
Merge pull request #105 from brandonbloom/blockly_cache_bust

Provide a cache_bust parameter to blockly
Move a few things off of the root page
[Finishes 59864640]: reset session with new /hoc/reset
Merge branch 'master' of github.com:code-dot-org/dashboard
Bypass asset pipeline for client code
Strip parsed revision
add milestone logging
Add LICENSE and NOTICE files
New translation help link
Text edits from Hadi
Loc fixes